On March 28 late evening, people across the world will switch off their lights to raise a collective voice against global warming. This is part of Earth Hour -- a global campaign to raise awareness about global warming and show support for action on climate change.

Organised by WWF, this is a worldwide campaign in which nearly 1,500 cities, including Delhi [Images] and Mumbai [Images], will switch off their lights on March 28 from 8.30 pm to 9.30 pm local time. The campaign is a symbolic event to send a strong message to our political leaders that we want them to take meaningful action on climate change.

This is the first time Indian cities will participate in the campaign. New Delhi and Mumbai have pledged their support to Earth Hour, and satellite Earth Hours have been planned in a host of cities. Actor Aamir Khan [Images] is face of the India campaign, and will switch off his lights at the designated hour. Several leading corporate houses such as HP India, HSBC, Wipro [Get Quote], Taj Hotels and ITC-Welcome Group have also lent their support to the campaign.

WWF India Secretary General and CEO Ravi Singh said, "Earth Hour is a unique initiative with which we hope to raise awareness and encourage people to make energy reduction a priority."

Earth Hour began in Sydney in 2007, when 2.2 million homes and businesses switched off their lights for one hour. In 2008 the message had grown into a global sustainability movement, with 50 million people switching off their lights. This year's target is to get 1 billion people to switch off their lights. Each participating household or business counts as one vote for the planet. The "votes" will be presented to world leaders at the Global Climate Change Conference in Copenhagen 2009, urging them to take action against global warming.

To participate in Earth Hour, sign up here (external link). And remember to switch off your lights on March 28 from 8.30 pm to 9.30 pm.